Massive red, dead galaxy spotted in young universe

Findings suggest need to reassess ideas about galaxy formation

RARE FIND Galaxy ZF-COSMOS-20115, illustrated here, may be an oddity in the early universe. It formed stars rapidly, but then suddenly shut off, becoming red and dead by the time the universe was only 1.65 billion years old.

Leonard Doublet/Swinburne University of Technology

A hefty red, dead galaxy in the early universe appears to have bulked up a bit too fast.

The galaxy, seen as it was when the universe was only 1.65 billion years old, weighs at least three times as much as the Milky Way, but has stopped making stars. Other galaxies at the time tend to be much smaller and continue to churn out stars. How such a monster was made in less than a billion years, then shut down so quickly isn’t clear, says Karl Glazebrook of Swinburne University of Technology in Australia. Finding the behemoth and possibly others like it may mean astronomers will have to rethink how galaxies are built to explain why some grow up fast, while others develop slowly, he and colleagues report in the April 6 Nature.

“The team has found an extreme galaxy, which is exciting,” says Peter Behroozi of the University of California, Berkeley, who was not involved in the study. The

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